Method for applying an adhesive, applicator device and product

Abstract

A method for depositing an adhesive diluted in a solvent, such as water, onto a substrate, such as a paper sheet (13) illustratively of cellulose wadding, and supported on and moving with a rotary cylinder (9) using a deposition apparatus (20) comprising at least one adhesive reservoir (23) and one cylinder transferring the adhesive onto the substrate, characterized in that the cylinder (25') does not have surface asperities and comprises first zones (25a) and second zones (25b) such that the quantity of adhesive dragged by the cylinder (25') onto the second zones is greater than the quantity of adhesive dragged onto the first zones.

We claim: 
     
       1. A method for depositing at least one adhesive diluted in a solvent onto a substrate for bonding said substrate to a second substrate comprising depositing said at least one adhesive diluted in a solvent onto a substrate by means of a deposition apparatus comprising a reservoir containing said at least one adhesive diluted in a solvent and a rotating cylinder for transferring said at least one adhesive from said reservoir onto said substrate, wherein said rotating cylinder comprises a relief-free surface having first zones and second zones such that said at least one adhesive is deposited onto the first zones in an amount which is less than an amount sufficient to form a bond between said substrate and a second substrate and said at least one adhesive is deposited on the second zones in an amount which is greater than an amount sufficient to form a bond between said substrate and a second substrate, thereby bonding said substrate to said second substrate. 
     
     
       2. A method according to claim 1 wherein said solvent is water. 
     
     
       3. A method according to claim 1 wherein said substrate is a paper sheet. 
     
     
       4. Method according to claim 1 wherein the second zones have an adhesive-wettability greater than the first zones. 
     
     
       5. Method according to claim 1 further comprising regulating flow of said at least one adhesive from the rotating cylinder so that the at least one adhesive deposited from said second zones of the rotating cylinder is in an amount sufficient to bond said substrate to a second substrate and the at least one adhesive deposited from the first zones is in an amount which is insufficient to bond said substrate to a second substrate. 
     
     
       6. Method according to either claim 1 or claim 5 wherein at least one substrate of said substrate and said second substrate is embossed and the at least one adhesive is deposited onto embossments of said at least one substrate. 
     
     
       7. Method according to claim 6 wherein the embossments are present in a density of 4-100/cm 2 . 
     
     
       8. Apparatus to implement the method according to claim 1 wherein said rotating cylinder is clad with an elastomer and said second zones are prepared by processing the rotating cylinder's surface to impart to the second zones greater wettability to the at least one adhesive diluted in a solvent than the wettability of said first zones on said rotating cylinder. 
     
     
       9. Apparatus according to claim 8 wherein the second zones of the rotating cylinder have a surface constituted of alveoles engraved in the elastomer. 
     
     
       10. A product produced according to the method of either claims 1 or 5 comprising two embossed substrates having a density of embossments between 4 and 100/cm 2 . 
     
     
       11. A product produced according to the method of claim 6 comprising two embossed substrates having a density of embossments between 4 and 100/cm 2 .